A joint effort by immersion cooling agency Iceotope and Meta, the mum or dad firm of Fb, discovered cooling arduous drives with a dielectric liquid is secure and a more practical technique of cooling than utilizing followers.
Hyperscalers like Meta deploy 1000’s of HDDs of their information facilities, and whereas the warmth given off on a person foundation is tiny, it provides up, particularly for the reason that drives are in fixed use and are shut collectively. The drives are saved in server racks that maintain nothing however dozens of arduous drives and are known as a JBOD (Only a Bunch Of Disks).
A JBOD can overheat with out cooling, which to this point has been accomplished with followers, however some drives have been additional away from followers than others, inflicting uneven cooling.
One factor that helped the experiment was a change in disk-drive manufacturing. Newer, excessive capability drives are full of helium to cut back vibration when spinning, and to maintain the helium in, the drives are hermetically sealed. What retains helium from leaking out additionally retains liquid from leaking in.
The check took a normal air-cooled, high-density JBOD storage system that held 72 3.5-inch arduous drives in a 40U rack, together with two single socket nodes, two SAS expander playing cards, a NIC, and an influence distribution board, and it was retrofitted for single-phase immersion cooling.
Iceotope doesn’t dunk the gear into tanks stuffed with coolant. As an alternative, it really works at chassis-level to precision ship a small quantity of dielectric fluid to the recent spots first earlier than cascading down within the chassis to take away the warmth from different parts. Consider it as partial immersion utilizing a fraction of the liquid required by tank immersion.
Iceotope used a fluorinated dielectric fluid with very excessive boiling level, nonetheless it has efficiently trialled artificial hydrocarbon dielectric fluids since this examine was performed. Iceotope says its know-how is liquid agnostic, and the corporate makes use of a spread of dielectric fluid varieties and suppliers.
Meta discovered the liquid-cooled system had a 5.4°F (3°C) variance in temperature among the many 72 HDDs no matter their location contained in the rack, a extra uniform consequence than with air cooling.
Iceotope stated the facility draw for air cooling and liquid cooling are pretty comparable at low load, however because the load will increase, immersion attracts much less energy than air cooling.
Meta is evaluating the advantages of Iceotope’s immersion cooling throughout its IT infrastructure. Server racks might be retrofitted to help liquid cooling with a minimal a price and energy, usually representing trivial percentages of the server price, in line with Iceotope, however liquid cooling nonetheless requires hermetically sealed drives.
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